BMI Calculator | Calculate Your Body Mass Index

Measurement System:

Weight (kg):

Height (cm):

Weight (lbs):

Height (feet): Height (inches):

Your BMI is:

BMI Categories:

Underweight: Less than 18.5

Normal weight: 18.5 – 24.9

Overweight: 25 – 29.9

Obesity: 30 or greater

Understanding Your BMI Results

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared.

BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.

BMI Categories and Health Risks

BMI Category	BMI Range	Health Risk Level
Underweight	Below 18.5	Increased risk of nutritional deficiencies and osteoporosis
Normal weight	18.5 - 24.9	Lowest risk of weight-related health problems
Overweight	25 - 29.9	Moderately increased risk of health conditions
Obesity Class I	30 - 34.9	High risk of developing serious health conditions
Obesity Class II	35 - 39.9	Very high risk of health complications
Obesity Class III	40 and above	Extremely high risk of life-threatening conditions

Limitations of BMI

While BMI is a useful screening tool, it has limitations:

It may overestimate body fat in athletes and others with a muscular build
It may underestimate body fat in older persons and others who have lost muscle mass
It doesn't account for factors like age, sex, ethnicity, and muscle mass

Frequently Asked Questions

What is a healthy BMI range?

For most adults, a healthy BMI falls between 18.5 and 24.9. This range is associated with the lowest risk of weight-related health problems.

How often should I check my BMI?

For most people, checking BMI every few months is sufficient unless you're actively trying to lose or gain weight. More important than frequent BMI checks is paying attention to overall health indicators and lifestyle habits.

Can BMI be inaccurate for muscular people?

Yes, BMI can categorize muscular individuals as overweight or obese even when they have low body fat. This is because BMI doesn't distinguish between muscle and fat mass.

Is BMI different for men and women?

The BMI calculation is the same for men and women, but interpretation may differ slightly since women typically have higher body fat percentages than men at the same BMI.